Anomalous properties of water near $4^\circ C$.

A given mass of water has minimum volume or maximum density at $4^\circ C$.

Amount of heat, $Q$ is proportional to

(i) mass of the substance, $Q \propto m$

(ii) Temperature difference, $Q \propto \Delta T$

$Q=\operatorname{Cm} \Delta T$

C specific heat capacity is expressed in $J/(kg -^{\circ} C)$

$C$ at constant pressure = $C_P$

$C$ at constant volume = $C_V$

$C_P > C_V$

The amount of heat that is required to heat up a substance.

$Q \propto m$

$Q \propto \Delta T$

$Q=\operatorname{Cm} \Delta T$

$C$ is called as specific heat capacity which depends on a particular material.

In a experiment to find the specific heat capacity of a block of metal of mass 0.2kg at $150^\circ C$ is dropped in a copper calorimeter $(m_{calorimeter} = 0.14kg)$ containing 0.25 kg water at $27^\circ C$. The final temperature is $40^\circ C$.

Compute the specific heat capacity of the metal.

$C_W=4.18 \times 10^3 \mathrm{J} /(kg-k)$

$C_C=0.386 \times 10^3 J/\left(kg-k\right)$

Data given:

$m_m = 0.2kg, Tm_1 = 150^\circ C, Tm_2 = 40^\circ C$

$(\Delta T)_m = Tm_1 - Tm_2 = 110^\circ C = 110k$

Heat lost by the metal block

$Q_m = C_m (0.2kg)(110k)= 22C_m J \quad ... (1)$

$\Delta E (\Delta T)_{W,C} = 40^\circ C - 27^\circ C = 13^\circ C = 13K$

$Q_T = Q_W + Q_C = M_WC_W(\Delta T) + M_CC_C(\Delta T)$

$(13.585 + 0.70^3) \times 10^3 J \quad ... (2)$

$Q_T = Q _m$

$C_m = 0.649 \times 10^3(J kg^{-1}k^{-1})$

Conversion of liquid into its gaseous form is called evaporation and the reverse process is called as condensation.

Solid to gas directly is called as sublimation.

Going from a gaseous phase to a solid phase is called as condensation.